<template>
  <div class="chartNum">
    <div class="box-item">
      <li
        v-for="(item, index) in orderNum"
        :key="index"
        class="number-item"
      >
        <span class="numBg">
          <i ref="numberItem">0123456789</i>
        </span>
      </li>
    </div>
  </div>
</template>
<script>
  export default {
    name: 'NumberFlip',
    props: {
      num: {
        type: Number,
        default: 0
      },
    },
    data() {
      return {
        orderNum: ['0', '0', '0', '0', '0', '0', '0', '0'], // 默认订单总数
      }
    },
    watch: {
      num(val) {
        this.toOrderNum(val)
        this.setNumberTransform()
      }
    },
    mounted() {
      this.toOrderNum(this.num) // 这里输入数字即可调用
      this.setNumberTransform()
    },
    methods: {
      // 设置文字滚动
      setNumberTransform() {
        const numberItems = this.$refs.numberItem // 拿到数字的ref，计算元素数量
        const numberArr = this.orderNum
        // 结合CSS 对数字字符进行滚动,显示订单数量
        for (let index = 0; index < numberItems.length; index++) {
          const elem = numberItems[index]
          elem.style.transform = `translate(-50%, -${numberArr[index] * 10}%)`
        }
      },
      // 处理总订单数字
      toOrderNum(num) {
        num = num.toString()
        // 把订单数变成字符串
        if (num.length < 8) {
          num = '0' + num // 如未满八位数，添加"0"补位
          this.toOrderNum(num) // 递归添加"0"补位
        } else if (num.length === 8) {
          // 订单数中加入逗号
          // num = num.slice(0, 2) + ',' + num.slice(2, 5) + ',' + num.slice(5, 8)
          this.orderNum = num.split('') // 将其便变成数据，渲染至滚动数组
        } else {
          // 订单总量数字超过八位显示异常
          this.$message.warning('订单总量数字过大，显示异常，请联系客服')
        }
      }
    }
  }
</script>
<style scoped lang='scss'>
  .numBg{
    background: url("../assets/images/flip_bg.png") no-repeat center center;
    background-size: 100% 100%;
  }
  /*订单总量滚动数字设置*/
  .box-item {
    position: relative;
    height: 50px;
    font-size: 38px;
    line-height: 38px;
    text-align: center;
    list-style: none;
    color: #2D7CFF;
    writing-mode: vertical-lr;
    text-orientation: upright;
    /*文字禁止编辑*/
    -moz-user-select: none; /*火狐*/
    -webkit-user-select: none; /*webkit浏览器*/
    -ms-user-select: none; /*IE10*/
    -khtml-user-select: none; /*早期浏览器*/
    user-select: none;
    /* overflow: hidden; */
  }

  /*滚动数字设置*/
  .number-item {
    width: 31px;
    height: 47px;
    /*background: #ccc;*/
    list-style: none;
    margin-right: 5px;
    /*background: rgba(250, 250, 250, 1);*/
    border-radius: 4px;
    border: 1px solid rgba(221, 221, 221, .1);

    & > span {
      position: relative;
      display: inline-block;
      margin-right: 10px;
      width: 100%;
      height: 100%;
      writing-mode: vertical-rl;
      text-orientation: upright;
      overflow: hidden;

      & > i {
        font-style: normal;
        position: absolute;
        top: 4px;
        left: 50%;
        transform: translate(-50%, 0);
        transition: transform 1s ease-in-out;
        letter-spacing: 10px;
      }
    }
  }

  .number-item:last-child {
    margin-right: 0;
  }
</style>
